The present invention relates to a golf club head, more particularly to a face structure capable of controlling the spring-like effect of the face portion without increasing the mass of the face portion, and a method for manufacturing the same.
Recent years, according to the Rules of Golf, golf club heads having a high spring-like effect can not be used. More specifically, the characteristic time of the club head shall not be greater than 239 microseconds with a test tolerance of 18 microseconds. In brief, the spring-like effect is such that when a ball hits the face portion of a hollow golf club head, the face portion is deformed and bounds the ball like a trampoline, and the initial ball speed of the ball is increased.
Accordingly, by increasing the rigidity of the face portion, the deformation at impact is lessened to lower the spring-like effect. The rigidity of the face portion can be increased by increasing the thickness thereof. But, if the thickness is increased, the mass of the face portion is increased accordingly, and the depth of the center of gravity of the head becomes decreased. As a result, motion of the club head at the time of off-center shots (miss shots) increases, and the directionality of the hit ball deteriorates.